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AIM

10/12/17

5−4−61

Arrival Procedures

lighting. Additionally, there are plans to replace

incandescent lamps with LEDs in approach lighting

systems.  Pilots should be aware that LED lights

cannot be sensed by infrared−based EFVSs. Further,

the FAA does not currently collect or disseminate

information about where LED lighting is installed.

l. Other Vision Systems. An Enhanced Vision

System (EVS) does not meet the requirements of an

EFVS. An EVS may present the sensor image on a

head−down display and may not be able to present the

image and flight symbology in the same scale and

alignment as the outside view. An EVS can also use

a HUD as its display element, yet still not meet the

regulatory requirements for an EFVS. While an EVS

that uses a head−down display or HUD may provide

situation awareness to the pilot, it does not meet the

operating requirements for an EFVS. Consequently,

a pilot cannot use an EVS in lieu of natural vision to

descend below DA/DH or MDA. Unlike an EFVS, a

Synthetic Vision System (SVS) or Synthetic Vision

Guidance System (SVGS) does not provide a

real−time sensor image of the outside scene and also

does not meet the equipment requirements for EFVS

operations. A pilot cannot use a synthetic vision

image on a head−up or a head−down display in lieu

of natural vision to descend below DA/DH or MDA.

An EFVS can, however, be integrated with an SVS,

also known as a Combined Vision System (CVS). A

CVS can be used to conduct EFVS operations if all of

the requirements for an EFVS are satisfied and the

SVS image does not interfere with the pilot’s ability

to see the external scene, to identify the required

visual references, or to see the sensor image.

m. Additional Information. Operational criteria

for EFVS can be found in Advisory Circular (AC)

90−106, Enhanced Flight Vision Systems, and

airworthiness criteria for EFVS can be found in

AC 20−167,  Airworthiness Approval of Enhanced

Vision System, Synthetic Vision System, Combined

Vision System, and Enhanced Flight Vision System

Equipment.

5−4−23. Visual Approach

a. A visual approach is conducted on an IFR flight

plan and authorizes a pilot to proceed visually and

clear of clouds to the airport. The pilot must have

either the airport or the preceding identified aircraft

in sight. This approach must be authorized and

controlled by the appropriate air traffic control

facility. Reported weather at the airport must have a

ceiling at or above 1,000 feet and visibility 3 miles or

greater. ATC may authorize this type approach when

it will be operationally beneficial. Visual approaches

are an IFR procedure conducted under IFR in visual

meteorological conditions. Cloud clearance require-

ments of 14 CFR Section 91.155 are not applicable,

unless required by operation specifications.

b. Operating to an Airport Without Weather

Reporting Service. ATC will advise the pilot when

weather is not available at the destination airport.

ATC may initiate a visual approach provided there is

a reasonable assurance that weather at the airport is a

ceiling at or above 1,000 feet and visibility 3 miles or

greater (e.g., area weather reports, PIREPs, etc.).

c. Operating to an Airport With an Operating

Control Tower. Aircraft may be authorized to

conduct a visual approach to one runway while other

aircraft are conducting IFR or VFR approaches to

another parallel, intersecting, or converging runway.

When operating to airports with parallel runways

separated by less than 2,500 feet, the succeeding

aircraft must report sighting the preceding aircraft

unless standard separation is being provided by ATC.

When operating to parallel runways separated by at

least 2,500 feet but less than 4,300 feet, controllers

will clear/vector aircraft to the final at an angle not

greater than 30 degrees unless radar, vertical, or

visual separation is provided during the turn−on. The

purpose of the 30 degree intercept angle is to reduce

the potential for overshoots of the final and to

preclude side−by−side operations with one or both

aircraft in a belly−up configuration during the

turn−on. Once the aircraft are established within

30 degrees of final, or on the final, these operations

may be conducted simultaneously. When the parallel

runways are separated by 4,300 feet or more, or

intersecting/converging runways are in use, ATC

may authorize a visual approach after advising all

aircraft involved that other aircraft are conducting

operations to the other runway. This may be

accomplished through use of the ATIS.

d. Separation Responsibilities. If the pilot has

the airport in sight but cannot see the aircraft to be

followed, ATC may clear the aircraft for a visual

approach; however, ATC retains both separation and

wake vortex separation responsibility. When visually

following a preceding aircraft, acceptance of the

visual approach clearance constitutes acceptance of

3/29/18

AIM